Fix upmake bug with conditions in bakefile files

Don't strip the <if> tags from bakefile variables (this bug fix is
actually in Makefile::Update Perl module, but is incorporated here by
reference) and remove these tags which somehow made it into upmake input
file, as they make no sense there.

Note also that upmake was recreated using a different version of fatpack
(0.010007), which accounts for many other differences in this file.

build/files

@@ -2067,7 +2067,6 @@ DFB_LOWLEVEL_HDR =
 
 OSX_LOWLEVEL_SRC =
     # Shared wxMac and wxCocoa files
-    <if cond="PLATFORM_MACOSX=='1'">
     src/osx/artmac.cpp
     src/osx/brush.cpp
     src/osx/dialog_osx.cpp
@@ -2091,12 +2090,10 @@ OSX_LOWLEVEL_SRC =
     src/osx/core/printmac.cpp
     src/osx/core/timer.cpp
     src/osx/core/utilsexc_cf.cpp
-    </if>
 
 OSX_LOWLEVEL_HDR =
 
 OSX_COMMON_SRC =
-<if cond="PLATFORM_MACOSX=='1'">
     # Common controls implementation
     src/osx/anybutton_osx.cpp
     src/osx/bmpbuttn_osx.cpp
@@ -2169,7 +2166,6 @@ OSX_COMMON_SRC =
     src/generic/prntdlgg.cpp
     src/generic/statusbr.cpp
     src/generic/textmeasure.cpp
-</if>
 
 # Header files like wx/osx/foo.h which include wx/osx/carbon/foo.h
 OSX_SHARED_HDR =